Add total support for I18N and for custom first weekday selection

[giraldezjorge]

Hi,
At first time, congratulations for this amazing component. I tried to make a similar component but you made it better than me xD

I did two commits to improve your calendar component:

• Add total support for I18N, including month names. Set "en" as default language. In case you don't add the customI18n object, or any property is not included, a default english value will be used.
• Allow to select the first weekday for calendar (month days and week names). For example in Spain the first weekday is Monday. With these changes you can select any day as first weekday.

I hope you like these two commits.

Regards

[giraldezjorge]

Oh sorry, travis failed because I forget to adapt the tests.

[coveralls]

Coverage decreased (-1.3%) to 89.12% when pulling 342eb9b on giraldezjorge:master into acd6b0b on Tinysymphony:master.

[giraldezjorge]

I fixed tests. They passed now

[coveralls]

Coverage decreased (-1.6%) to 88.813% when pulling 527491a on giraldezjorge:master into acd6b0b on Tinysymphony:master.

[coveralls]

Coverage decreased (-1.5%) to 88.939% when pulling 9297914 on giraldezjorge:master into acd6b0b on Tinysymphony:master.

[coveralls]

Coverage decreased (-4.7%) to 85.745% when pulling 2ed1bf8 on giraldezjorge:master into acd6b0b on Tinysymphony:master.